Double-plunger valve



. `w. LARNl-:R

DOUBLE PLUNGER VALVE July 19, 1927. 1,636,661

Filed May 6. 1921 fr i 'Patented July i9, 1927.

lururan sTa'rEs A PAiiN-:NT'I'olii-liza CHESTER W. LARNEB, FPHILADELPHIA, PENNSYLVANIA, ASSIGNOR., BY MESNE AS- SIGNMENTS, T0 I.IP.l MOBRISVCOBPOBATION, A CORPORATION OF DELAWARE.

DoUBLn-PLUNGER vALvn Application nled v:Inlay 8,

The nature' and 'objects'of thev present invention'will appeal` from thefollowing description which will be made with reference to theaccompanying drawings forming part hereof and in which t Figure 1 is aview principally 1n section.

yFig. 2 is a view principally in section showing a modification, and

Fi 3 is ai detached sectional View of a This invention consists of adouble plunger valve adapted to operate under conditions l'of fiow ineither direction. Fig. 1 shows one embodimenthaving a body or casing 1contracted at both ends with radial ribs 2 integralwith the casingl andbored out to support in proper postlonan internal cylinv der 3 havingapartition -or bulkhead 4 separating the space within the cylinder 3into two( chambers 5 and 6.

The internal cylinder 3 contains plungers `7 and 8 sliding within it andclosing against seats 9 and 10 at each' end of the body 1 to stop theHow through the body. Plunger 7 closes against seat 9 to stop flow fromright to left in the" ligure and plunger 8 closes against seat 10 tostop theow in the opposite direction. Plungers 7 and 8 are rigidlyconnected' together by a hollow strut 11 ao attached to each plunger bynose pieces 12.

Strut 11 has a centra bore which contains rod 13 and has a recess at thecenter in which a rack 14 slides longitudinally.

, The nose pieces :12 `1ere provided with a5 lapertures 15 for theurpose of discharging pressure from cham ers 5 and `6 into the conduitand the discharge of pressure through these apertures is controlled bythe motion ot rod 13 which may lbe utilized vto ce open or close Jeitherof these apertures" ac- 1 cording to` the direction in which it ismoved.

Rack 14 isfrigidly connected to*l rod 13 b pins 16 or by other` suitablemeans. ,pinion 17 engages rack 14 and moves it in as either directionaccording to Whether it, is

desired to close plunger 7 or plunger 8. Pinion 17 is mounted on a shaft18 which passes through cylinder 3 and bodyv 1 and is 'operated bysuitable mechanism from the 5@ outside of the valve. I

When there is flow or tendency to iow in.

the conduit plungers 7 and 8 are opened and closed in the mannerdescribed in my retained. Pinion 1.7 engages two racks 14.a connected torods 13a which operate plun ers 1921.. Serial No. 467,417.

^ jacent end of the rod 13 by differentiating the pressure in thechamber 5, provided past the plunger 8 a'nd through the Huid way betweenthe body and cylinder and thence by the clearance between the plunger 7and cylinder, with thepressure on the outside of the nose of the plunger7, the operation-of the plunger 8 being the same.I When the con- 05 duitis empty or there is no tendency to flow, however, the operation isslightly different. Plunger 7 is then closed by moving rod 13 tothe'left, the end of rod 13 abutting against its seat at aperture 15,and is opened by reversing the movement of rod 13 unt-il the other endof. the rod abuts against the seat at aperture 15 in plunger 8. Theoperation of plunger 8 is the reverse of the operation of plunger 7.

When flow or tendency to flow is from right to left in. the drawin it iscontrolled by the operation of plunger pressure being exhausted from orretained in chamber 5 which is separated from chamber 6 by partition 4which fits closely around strut 11 1n order to prevent excessive leakagebetween chambers 5 and 6. When plunger 7 is being operated plunger 8 isinert and vice versa.

Figure 2 shows another embodiment of this invention in which plungers 7and 8 are not rigidly connected together as in Fig. 1. In this case whenone plunger is closed the other is'a'lso closed and when one is open theother is also open. VThe principle of using the lefthand plunger tocontrol flow Vfrom right yto left and the rightha'nd plunger to controlflow from left to right, however, is

7 and 8 in the manner described in copen ing application, Serial N o.294,155. In this case the rods 13a have enlarged ends 19 which areutilized to pull plungers 7 and 8 open by abutting against bearings 20connected to the .plungers, whenever-there isv no flow or tendency toflow in the conduit.

It is clear that if, for example, iiow is occurring from rightto left inthe'fi re and plunger 7 is closed under these con itions it .cases beomitted. Assuming then,

'flow from right vto left and it is will be held tightly to its seat bypressure in chamber 5 admitted through .they clearance between plunger 7and cylinder 3. At the same time, although plunger 8 is closed it is notheld against its seat by difference of pressure but merely by thepressure of 19 against the seat'of aperture 15. This pressure,particularly in view of the unavoidable lost motion in the gearing, isnot suficient u to prevent leakage past the seat of plunger 8 and thisleakage maintains pressure linside of body 1 and in chamber 5 to holdlunger 7 tightly closed.;-

e same is true when plunger 8 closedA if the source of pressure is inthe conduit to a preponderance of pressure on the outside of theplunger. Plunger 8 is also unseated and opens as rfast as its rod 13a iswithdrawn, but in this case the entire outside surface o the plungernose is subjected to full pressur and owing to the reduction of pressureinside the plunger, the plunger is pressed against the end 19 of rod 13awhich'alone restrains the movement of the plunger. This throws a heavystrain upon the racks 14 and the pinion 17 and its operating mechanism.For this reason it is advisable to use thepartition 4 excepting possiblyin the case of small valves.

Fig. 3 shows a modification in that por# v tion of bodyvl and plungers 7and 8 adjacent to the plunger seat which is under certain circumstancesadvantageous.

Under some conditions and particularly when these valves are used withgases instead of liquidstliere may be some tendenc toward uneven orerratic movement o the plunger as it approaches the closed position andis subjected to sudden changes of pressure on the exposed area of theplunger which lies within the seat. This in the case of gas valves isdueto the elasticity of the gas and the fact that the plunger will moveas a result of the expansion or contraction of^ i the gas before.suiicient time has elapsed'to permit sufficient flow to take placethrough aperture 15 toequalize the pressures inside and outside of theplunger.

In Fig. 3 a shoulder 21 is provided uinside `body 1 adjacent to theseatand a corresponding recess22gis provided in the plunger. The cylindricalsurface of recess 22 fitsiinto 'the cylindrical surface of\shoulder 21with a small clearance and thus practically ystops with the 1,sse,ee1

those matters or otherwisethan as the prior art and the appended claimsmay require.

I claim: v 1.'A doubleplunger valve operative with flow in eitherdirection and comprising in combination a body contracted at each endand having plunger seats and provided with an internal cylinder spacedfrom it to provide a fluid Way, two plunger chambers sepa-I rated by abulkhead or partition provided in the cylinder, two plungersco-operating .with

the chambers and seats and past one of which pressure is available inthe fluid way and in` the chamber of the other, and valved aper-y turesthrough the lungers for differentiating said pressure in the chamberfrom the pressure on the outside of the corresponding plunger to operatethe latter. i 2. A double plunger'valve operative with .flow in eitherdirection and comprising in combination a body contracted at each endand having plunger seats and provided with an internal cylinder spacedfrom it to provide'a fluid way, two plunger chambers separated by abulkhead pr partition provided in the cylinder, two plungersco-operating with the chambers-and seats and past one of which pressureisF available in the fluid way andv in the chamber of the other, valveda etating said pressure 1n the chamber from the pressure on the outsideof the corresponding plunger to operatel the latter by fluid pressure,and mechanical means accessible ertures through the plungers fordifferfrom the outside'f the body and connected lungers and adapted tooperate them in t eabsence of fluid pressure sufficient to move theplungers.

' 3. A; double plunger valve operative with flow in either direction andcomprising in combination a body contracted 'at each endplunger seatsand provided with and havin l cylinder spaced from it to lproan internavide a fluid way, two plunger chambers sep;

man by a bulkhead 0r partition provid-ed, f

in the cylinder, two plungers cti-operating -with, the chambers andseats and past one of' `which pressure isy available inthe fluid Way andfn apertures through the plungers fordifferenltiating said pressure inthe chamber from the pressure on spending plunger `the outside of thecorre'- to' operate the latter,` a l the chamberof the other, valvedstrut for holding the plungersin spaced operating chamber therefor, avalve seat and a shoulder onsaid tapering portion comprisingasubstantially cylindrical surface projecting from saidseat .toward thevalve plunger, said hollow valve plungerbeing provided with acylindrical surface adapted to lit in the cylindrical portion of saidshoulder and also having a connection from its interior to thefluid-Way. below said seat,

l the tapering portion of said conduit is adapt- 2o whereby said plungerin cooperation with ed to gradually cut off fluid-flow through saidconduit and thereafter beingr adapted t6 move .the length of saidcylindrical recess before said seat is engaged, and said interior iconnection, during movement or the plunger through said cylindricalrecess, being adapted to permit commuicatiolibetween said chamberand thefluid-Way below said seat,

' thereby tov reduce the operating fluid pressure in said chamber andpermit a gradual Aretardation of the plunger so that'said sefdt isengaged relativelyeasily.

5. Ai double plunger'valve adapted to stop and to regulate ilow ineither direction having in combinationmeans comprising adjus'tahleapertures through the plungers to automatically balance the fluidpressures acting on the plungers to hold them stationary at any desiredposition or to unbalance Said fluid pressures. to move said plungers,and mechanical means to move said plungers when said fluid pressuremeans are insullicient.

6. A double plunger valve operative with flow in either direction andcomprising in combination a body contracted at each end and havingplunger seats and provided with an internal cylinder spaced from it toprovide a fluid Way, two plunger chambers separated by a bulkhead orpartition provided in the cylinder, two plungers co-operating with thechambers and seats and fpast one of stationary cylindrical housingspaced from said casing to form a fluid Way therebetween,,oppositelydirected l movable valve i plungers slidably vsupprted by said housingand adapted to engage said seats, iuidy r ers may be controlled ineither direction.

pressure operated means within'said housing for movin said plungers inunison with each other in t e same direction so that when one plungercloses the other opens.

8. The combination with a conduit casing having oppositely disposedvalve seats, of a stationary cylindrical housing having op- `positelydirected movable valve plungers adapted to engage said seats, andmechanical means having c ontrolling- -means movable relative to saidplungers while dis osed within said housing for moving said p ungers inunison with each other lin the `samedi'rection so that when one plungeropens the, other plunger closes. l

9. The combination with a conduit casing having oppositely disposedvalve seats, 'of a stationary cylindrical housing spaced .from saidcasing to form a fluid waytherebetween," oppositely directed movablevalve plungers slidably supported by said houslng and adapted to 'engagesaid seats and combined .mechanical and fluid pressure means within saidhousing for moving said plungers in unison with each other, in the samedirection so that when one plunger closes the other opens.

10. The combination with a conduit casi ing having oppositel directedvalve seats of a stationary cylin, rical housing between said seats,movable valve plungers sliding in said. housing and seatlng against saldseats,

"ssidseats, movable valve plungers sliding in said housing and seatingagainst said seats, andvluid' pressure operated means for moving saidvalve plungers comprising means for balancin the pressures on oppositesides of one of sald plungers and simultaneously unbalancingthepressures on the other of said plungers and means connecting said valvelungers to move in unison.

12. e combination with a conduit casing having oppositely disposed valveseats, of a cylindrical houslng for containing Huid pressure, oppositelydirected Llvalve plungers adaptedto engage said seats and movabiysupported by said housing, and means adaptp edto move with said plungersfor controlling the discharge of lluid contained'in said housing wherebymovement of said plung- 13. The combination with a conduit casing havingbppositey disposed .valve seats,l of a stationary cylin rical Huidcontaining housing having oppositely directed valve means, movabl'ysupported thereby and adapted to engage 1said seats, and means ada tedto move withv said plungersffor control ing theiuidpressure within saidhousing, wherebv.

the movable valve means may be controlled in either direction.4 14. The'combination with a. conduit cas- .ing having oppositely disposed valveseats,

of a stationary cylindrical lu'id containing housing having oppositelydirected valve means, movably supported thereby and adaptedto engag saidseats, and ,means for moving said valve meansin opposite di hollowportion of said plungers to move the meansv for controlling t lsame inoposite directions, said latter means inclu ing valve means forcontrolling the fluid pressure in said hollow plungers,

and mechanical actuating means en rtendlng.

from said plungers and interme'- laterally diate their ends forcontrolling the fluid therein.

16. The combination with a-conduit casing havingoppositely disposedvalve seats, of oppositely directed ported hollow valve lplungersadapted to en age said seats, and e'ports of each of move with saidvalvemeans the oppositely` directed plungers wherebyA plunger movement may becontrolled.

17. The combination with a conduitcasing having oppositely disposedvalve seats,

of a. stationary central member,

directed ported hollow valve plungersmovoppositely y j ably'supportedthereby and adapted tc'en;

gage said seats, means whereby fluid' pres- 3'y sure may be admitted tosaid hollow plungers, and means for controlling the ports oi trolled.

18. The combination'with a conduit casing having'oppositely disposedvalve seats.

, of a stationary central' supporting member.

o positely directed hollow .ported valve p un ers movably supported bysaid central j mem er and adapte to engage said seats, the ports of saidplungers extending in opposite directions, and movable means openin aport 1s closed plunger movement will occur in the direction which saidport closing means moves.

19. The combination with a conduitl casing having oppositely disposedvalve seats, of a stationary central supporting member, oppositelydirected hollow movable valvep ungers adapted toengage said seats, saidplungers having ports -extending' in opposite directions, and movablemeans for closing said ports, whereby plunger movement is effected inthe direction of movement of the port closing means.- A

CHESTER W. LARNER.

1each of the op'positely `directed plungers whereby plunger movement maybe Y coml for or closingaid ports whereby whew

